I don't know if Toyota would do it for this department, but they 'sponsor' the ones used in San Diego for beach patrol. So, it could be one of those that are sold from one department to another, or it was an outright push from the manufacturer.
Plus, being a fleet manager in a government agency, I can vouch that the government price would be a good deal less than the deals you and I can walk into a dealership and get. Plus with the lower prices, options are easier to add if there's even the slightest reasonable request. Or even a package deal that has a rebate attached to it for upgrades.
I spoke with one of the SDFD lifeguards, and they have an excellent point for having crawl control, etc. when they're in the sand. They even train with the 4R's in a pile of loose sand to understand A-Trac and crawl control.